1. Spitzer Constraints on Primordial and Debris Disk Evolution John Carpenter on behalf of the FEPS collaboration D. Backman (NASA-Ames) S. Beckwith (STScI) J. Bouwman (MPIA) M. Cohen (UC-Berkeley) U. Gorti (NASA-Ames) T. Henning (MPIA) L. Hillenbrand (Caltech) D. Hines (Space Sci. Inst) D. Hollenbach (NASA-Ames) J. Kim (Arizona) J. Lunine (LPL) R. Malhotra (LPL) E. Mamajek (CfA) M. Meyer (Arizona) A. Moro-Martin (Princeton) P. Morris (SSC) J. Najita (NOAO) D. Padgett (SSC) I. Pascucci (Arizona) J. Rodmann (MPIA) M. Silverstone (Arizona) D. Soderblom (STScI) J. Stauffer (SSC) B. Stobie (Arizona) S. Strom (NOAO) D. Watson (Rochester) S. Weidenschilling (PSI) S. Wolf (MPIA) E. Young (Arizona)

2. Parameter Space for FEPS and Upper Sco Stellar Age (Myr) 533000 0.1 20 1 Stellar Mass (Msun) FEPS (314 + stars) Upper Sco (205 stars)

3. Disks vs. Stellar Mass at 5 Myr Stellar Mass Excess

4. FEPS: 8  m excesses < 1.3% excess (3  ) for < 100 Myr Excess See also Silverstone et al. (2006)

5. FEPS: 24  m excesses 3  = 12%

6. 24  m Excess Fraction vs. Age

7. 70  m Excess Fraction vs. Age

8. Dust temperatures

9. IRS Dust Temperature vs. Age

10. Debris Disk Models Kenyon & Bromley (2005) Terrestrial Planet FormationKuiper Belt disks

11. Evolution of Hot Dust FEPS 8  m limit (3  ) Dominic & Decin (2003) Wyatt et al. (2007)

12. Evolution of Warm Dust

13. Evolution of Cool Dust

14. Gas Dissipation Timescales Pascucci et al. 2006 H2H2 H2H2 S I H2H2 Si II Fe II

15. Gas Dissipation Timescales Pascucci et al. 2006 < 0.04 M Jup in inner disk for ages 10-100 Myr < 2 M earth between radius of 10 and 40 AU

16. Summary Primordial disks survive longer around low mass stars 12% solar mass stars with > 12% excess at 24  m for < 300 Myr Decline in 24  m excess fraction > 300 Myr Uranus/Neptune-mass planets form by 100 Myr